In the related art, as shown in FIG. 5, a hybrid turbocharger 100 is known which is provided with a turbine 101 which is driven by exhaust gas discharged from an internal combustion engine such as a ship diesel engine, a compressor 102 which is driven by the turbine 101, thereby pressure-feeding outside air to the internal combustion engine, and a motor/generator 103 which is connected to a rotary shaft of the turbine 101 and the compressor 102. The hybrid turbocharger 100 obtains generated power by using exhaust gas which is discharged from the internal combustion engine, not only as a compressor driving force of a turbocharger, but also as power for driving the motor/generator 103. Alternating-current generated power obtained by the motor/generator 103 is converted into direct-current power by a first power converter 104, and then, converted into three-phase alternating-current power having a frequency corresponding to a ship electric grid 106 by a second power converter 105, and supplied to the ship electric grid 106.